2N4929 bipolar transistor — Specifications & Equivalents

About the 2N4929

The 2N4929 is a PNP bipolar transistor with a collector–emitter voltage (V_CEO) rating of 150 V, a continuous collector current (I_C) of 0.5 A and a DC current gain (h_FE) of 25–200. It can dissipate up to 5 W and is rated to a junction temperature of -65 to +200°C. It is supplied in the TO-39 package.

At a glance

• Type: PNP bipolar transistor
• Max collector–emitter voltage (V_CEO): 150 V
• Max collector current (I_C): 0.5 A
• DC current gain (h_FE): 25–200
• Transition frequency (f_T): 100 MHz
• Power dissipation (P_D): 5 W
• Max junction temperature (T_J): -65 to +200°C
• Package: TO-39
• Manufacturer: Multi-source (JEDEC registered part number)

Typical applications

Judging from its ratings the 2N4929 is generally applied in RF and high-speed switching stages and small-signal amplification and general-purpose switching.

A transition frequency (f_T) of 100 MHz indicates the frequency range over which useful current gain remains available.

The quoted current gain of 25–200 determines the base drive needed: divide your target collector current by the minimum h_FE, not the typical figure, when sizing the base resistor.

Biasing and absolute maximum ratings

Absolute-maximum breakdown limits are V_CEO 150 V, V_CBO 150 V and V_EBO 4 V (magnitudes). As a PNP device these are negative with respect to the emitter, so the collector sits below the emitter in normal operation. The emitter–base rating is the easiest to overlook and is often only a few volts, so protect the junction against reverse drive.

Dissipation is capped at 5 W, and that figure assumes the datasheet's mounting and ambient conditions — derate it for your own thermal design.

Choosing a replacement for the 2N4929

A drop-in substitute for the 2N4929 must be the same PNP type and offer a collector–emitter rating of at least 150 V, a collector current rating of at least 0.5 A, current gain in the same ballpark as 25–200 and a transition frequency of at least 100 MHz for the same bandwidth.

Mechanically, check the replacement against the TO-39 footprint and confirm the pin order — parts sharing a package outline do not always share a pinout.

Because 2N4929 is a JEDEC-registered part number rather than one vendor's proprietary series, it is produced by several manufacturers. Datasheet figures vary slightly between them, so check the datasheet of the brand you actually buy — this also makes like-for-like sourcing easier.

Where the application switches inductive loads or runs near the voltage limit, keep extra headroom rather than choosing a part that only just meets the original numbers.

Frequently asked questions

What is the 2N4929?

The 2N4929 is a PNP bipolar junction transistor (BJT). It is rated for 150 V collector-emitter and 0.5 A continuous collector current.

What is the maximum voltage of the 2N4929?

Maximum collector-emitter voltage (Vceo) is 150 V, and collector-base (Vcbo) is 150 V.

How much current can the 2N4929 handle?

Continuous collector current is rated at 0.5 A, with dissipation limited to 5 W.

What is the hFE of the 2N4929?

DC current gain (hFE) is quoted as 25–200. Size base drive from the minimum value so the transistor saturates fully across production spread.

What package does the 2N4929 come in?

It is listed in TO-39. Verify the pinout of the specific variant, as one outline can carry different pin assignments.

What can I use to replace the 2N4929?

No verified equivalents are listed yet. Choose a part of the same polarity that meets or exceeds every rating above and shares a compatible package and pinout.